【tomcat启动失败问题】Unable to start embedded Tomcat

启动spring boot 项目后抛出如下异常:

 org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
     at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:536) ~[spring-context-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
     at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at com.jiajian.JerseyTestDemoApplication.main(JerseyTestDemoApplication.java:10) [classes!/:0.0.1-SNAPSHOT]
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
     at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
     at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
     at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
     at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
     at org.springframework.boot.loader.WarLauncher.main(WarLauncher.java:59) [jersey-test-demo-0.0.1-SNAPSHOT.war:0.0.1-SNAPSHOT]
 Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
     at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:115) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:82) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:535) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:177) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     ... 16 common frames omitted
 Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
     at org.apache.catalina.startup.Tomcat.start(Tomcat.java:356) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
     at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:96) ~[spring-boot-1.4.2.RELEASE.jar!/:1.4.2.RELEASE]
     ... 21 common frames omitted
 Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
     at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:791) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
     at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
     ... 23 common frames omitted

原因是因为项目中引用了

<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>

tomcat7依赖中也有此包，造成多次引用依赖导致的jar包冲突导致的报错，只需将pom.xml中的干掉就可以了，不再冲突了，就可以快乐地写 RESTful风格的API提供给客户端or服务端调用了， so easy !